iwlwifi: mvm: support init extended command

When we load firmware in extended mode (as we do by default for
now) driver should send a command what kind of commands ucode
should stop and wait for before proceeding with phy calibrations.
Support this command. Currently we only do NVM access - so mark
this bit only.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>